https://www.techradar.com/news/analyst-says-the-iphone-will-get-a-triple-lens-camera-in-2019

We're already seeing phones upping the ante by building rear cameras from three lenses instead of the usual two, but that's not an innovation Apple is going to rush to follow, according to reports – it's going to wait until the 2019 iPhone line-up to install three lenses on the back of its own devices.

That's according to a research note from Deutsche Securities analyst Jialin Lu, via the Taiwanese Economic Daily News, via MacRumors. It's all going to serve the iPhone's 3D depth-sensing and augmented reality capabilities, something we know Apple has a fondness for.